ANATOMIA FOLIAR DE FORRAGEIRAS E A RELAÇÃO COM O VALOR NUTRITIVO

Additional procedures in the study of grasses are needed to improve animal performance in tropical regions of Brazil, as the increase in voluntary forage intake is related to the volume of the cell wall in leaf blades, referring to the vascular tissue, sclerenchyma, parenchyma bundle sheath cells, the C4 grasses which have become well developed and can influence the accessibility of rumen microorganisms. Added to this fact changes in nutritive value and sward structure, which vary throughout the seasons and can be correlated to the proportion and distribution of these tissues. This tissue differs in the plant by several factors, one of them is the presence or absence of secondary cell wall, another important factor is the arrangement that exists between them and that can generate barriers to the ruminal microorganisms, limiting digestion. So it is very important to know the anatomy of the forage, not only with the aim of adapting management strategies, physical and chemical treatments, selection and breeding of forage, but also explain the responses obtained with the animal performance, and the latter perhaps the main goal of understanding these barriers through the study of leaf anatomy. This review aims to expose some differences between C3 and C4 plants cycle, with main emphasis on anatomical characteristics evaluated by light and electron microscopy, as well as demonstrating the importance of the tissues that form the leaf blades and their specific functions